Native like structure and stability of apo AI in a n‐propanol/water solution as determined by 13C NMR

FEBS Letters

Wieruszeski, Jean-Michel¹  Lippens, Guy¹  Fruchart, Jean-Charles²  Leroy, Arnaud²  Parra, Henri-Joseph² 

[1] URA 1309 CNRS-SCBM, Institut Pasteur de Lille, 1 rue du Professeur Calmette, 59019 Lille CEDEX, France;SERLIA et INSERM U 325 Institut Pasteur de Lille, 1 rue du professeur Calmette, 59019 Lille CEDEX, France

关键词: Apolipoprotein AI (Human);    n-Propanol;    Conformation;    13C dimethyl-Lys NMR;    apo AI;    apolipoprotein AI;    HDL;    high density lipoprotein(s);    rHDL;    reconstituted HDL;    POPC;    palmitoyl-oleoyl-phosphatidyl-choline;    TMSP;    trimethyl-silyl-2;    2′-3;    3′-d-propionic acid;    sodium salt;    NMR;    nuclear magnetic resonance;   

DOI  :  10.1016/0014-5793(95)00134-U

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

To elucidate the molecular details of the conformation of apolipoprotein AI (apo AI), we have developed an approach related to the solubilization of this protein in 30% n-propanol. We have previously reported the promotion of a native-like structure for apo AI solubilized in n-propanol, as depicted by circular dichroism, fluorescence, and limited proteolytic digestion as compared to the lipid associated form of apo AI. In the present study, we labeled the Lys residues of apo AI with ¹³C by reductive methylation and used ¹³C NMR to confirm the formation of a native-like structure of apo AI in this environment. Furthermore, by the above criteria (circular dichroism and ¹³C NMR) and by using urea and temperature as denaturing agents, we show that the denaturation of the native-like structure of apo AI in n-propanol is a biphasic process. These studies show that in 30% n-propanol, apo AI contains two independently folded structural domains, of markedly different stabilities that might correspond to the amino-terminal and the carboxy-terminal halves of the molecule.

【 授权许可】

Unknown